CH

www.vishay.com

Vishay Sfernice

Revision: 28-Aug-13

5

Document Number: 53014

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

The complex impedance of the chip resistor is given by the following equations:

Notes

•

 = 2 x  x f

• f: Frequency



The chip resistor itself is purely resistive when

. The smaller the L x C product the greater the frequency range over

which the resistor looks approximately resistive.



This can be seen on the graphs showing the ratio

versus frequency.



R, L and C are relevant to the chip resistor itself.



C. This combination can upgrade or downgrade the HF behaviour of the component.



This is why we are displaying two sets of data:

•

versus frequency curves which aims to show at a glance the intrinsic HF performance of a given chip resistor

• S-parameters versus frequency curves relevant to chip resistor when assembled on ideal Z0 impedance transmission line

configurations please consult us).

Equivalent circuit for S-parameters:

Z

R

j

 L

R

2

C

–

L

2

C



2

–



+

1C R

2

C

2L

–



2

L

2

C



4

+



+

--------------------------------------------------------------------------------------

=

Z



R

--------

1

1

C R

2

C

2L

–



2

L

2

C



4

+



+

------------------------------------------------------------------------------------------ x

1

 L

R

2

C

–

L

2

C



2

–



R

------------------------------------------------------------

2

+

=



tan

1

–

 L

R

2

C

–

L

2

C



2

–



R

------------------------------------------------------------

=

R

L

C

----

=

Z



R

--------

Z



R

--------

L

c

C

g

Z

0

C

L

R

Z total

Z

0

L

c

Z

S

G

Z

L

C

g